Presently, the North American domestic laundry washing machine market (as well as to some extent, that of the global laundry market) is divided into two main types of washing machines: (1) “top-loading” or “vertical “axis” configuration and (2) the “front-loading”, “high efficiency” (“HE”) or “horizontal axis” washing machines. Until recently, the horizontal axis washing machines were found more often in European households but have recently garnered more success in the North American market due in part to stricter energy and water consumption regulations which have increased the portion of new machines sold having the front-loading configuration. However, as the rate of washing machine replacement is typically very slow (many consumers wait until their old machine no longer functions to replace it), it is expected that the duality of machines will continue for quite some time.
Because of this duality of the washing machines used by North American consumers, particularly in the United States, but indeed to some extent, consumers globally, there is a consumer need for laundry detergents suitable for use in each type of machine. To a large extent, the domestic laundry detergents currently commercially available are formulated for one or the other type of machine, not both. This duality of product formulation is not without reason or consequence.
The reason for providing two types of detergents is often due to manufacturer's attempts to provide the in-wash suds profile that is consumer expected while still ensuring that the detergent will properly function with each type of machine. While it may seem strange, consumers have come to associate suds with cleaning and therefore laundry detergent manufacturers must ensure the right amount of suds during the wash cycle is observed to meet consumer's expectations. If the incorrect level of suds is created, the consumer may altogether stop using a detergent, even if it provides the appropriate cleaning.
The formulations currently sold for top-loading washing machines are typically higher sudsing and can be more easily formulated from better-cleaning surfactant compositions with low or no fatty acid (soap) or nonionic surfactant. In contrast, front-loading washing machines typically cannot have high sudsing during the wash cycle due to engineering constraints. Manufacturers of such machines have put suds detectors in place to ensure that the machines do not leak during the wash cycle. Machines will typically shut off (“suds lock”), at least temporarily, during high levels of suds creation to allow the suds to dissipate. Therefore, under most circumstances, if a top-loading detergent is used in a front-loading machine, the machine will either operate very slowly (stopping several times during the cycle to allow suds to subside) or will shut down altogether. Either result is extremely frustrating to the consumer.
Detergent manufacturers have addressed this problem by developing separate detergent formulations for front-loading washing machines. Such front-loading, high efficiency laundry detergents or “HE laundry detergents” are often sold in the same store area of North American stores as are the historical front-loading formulations but are marked by a consumer-recognizable “HE” symbol.
One such method of suds-control is to increase the level of fatty acid and/or nonionic surfactant in the formulation. However, while this may be a simple sounding solution when you are referencing just one formulation, it becomes logistically very difficult when trying to make two different types of formulas for each of the many different detergent formulations, scents, and types of cleaning. Furthermore, having two different formulations which are similarly marketed to consumers can also cause consumer confusion and dissatisfaction if the wrong product is purchased by accident.
Therefore there is a need to provide one single laundry detergent composition that can meet consumers' needs in both types of machines.
Furthermore, traditionally top loading formulas can be higher sudsing and contain more of the better-cleaning surfactant systems containing low or no fatty acid (soap) or nonionic surfactants. However, to control suds in the HE formulations, greater amounts of these materials are typically used and can result in decreased cleaning capability of the formulation.
Therefore, there is a need to provide not only one single laundry detergent composition for both top loading and HE machines but to also provide a composition that provides good cleaning.